Rows of invaders are moving down the screen with maths questions inside them. Can you load your gun with the right answer and shoot them before they land?

You can choose questions on addition, subtraction, multiplication, division, or a combination of any of these.

Fifty speed levels and nine levels of difficulty allows each child to play at his own standard - but they'll soon be playing on higher levels!

Hours of education al fun for children of 4-12 years old.

When the program behings you ar asked to choose three keys to move the base left, right and to fire. Just press the three keys you want to use. (Any alphabet key, cursor key or the space bar is allowed. A good combination is Z - Left, X - Right SPACE - Fire.)

Next, you are asked if the computer should make up the questions. If you answer 'no' then instructions for typing in your own questions will appear on the screen.

If you answer 'yes' then you are asked what type of questions you want to be asked - type 'Y' of 'N' to the four choices depending on which you want.

You are then given three choices for how the game will progress (1) Invaders will get faster as you clear each screen, (2) Questions will get harder as you clear each screen. (3) both (1) and (2).

The final two questions allow you to choose a speed and difficulty level.

20 is a reasonable speed level to start with.

An approximate guide to difficulty level is:-

If the invaders land, you can press SPACE to try again on the same level, C to change level or E to exit.

Pressing BREAK will restart the program.